• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2002년도 학술발표대회
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• pp.39-61
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• 2002

Bacteria and fungi are fundamental biotic components of natural biogeochemical cycles for metals and metalloids and play important roles in dissolution, precipitation, oxidation and reduction processes. Some processes catalyzed by microorganisms also have important applications in environmental biotechnology in the areas of ore leaching and bioremediation.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.323-331
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• 2003

Bacteria and fungi are fundamental biotic components of natural biogeochemical cycles for metals and metalloids, and play important roles in dissolution, precipitation, oxidation and reduction processes. Some processes catalyzed by microorganisms also have important applications in environmental biotechnology in the areas of ore leaching and bioremediation.

• Journal of Ecology and Environment
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• 제44권2호
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• pp.81-89
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• 2020

In the forest ecosystems, litterfall is an important component of the nutrient cycle that regulates the accumulation of soil organic matter (SOM), the input and output of the nutrients, nutrient replenishment, biodiversity conservation, and other ecosystem functions. Therefore, a profound understanding of the major processes (litterfall production and its decomposition rate) in the cycle is vital for sustainable forest management (SFM). Despite these facts, there is still a limited knowledge in tropical forest ecosystems, and further researches are highly needed. This shortfall of research-based knowledge, especially in tropical forest ecosystems, may be a contributing factor to the lack of understanding of the role of plant litter in the forest ecosystem function for sustainable forest management, particularly in the tropical forest landscapes. Therefore, in this paper, I review the role of plant litter in tropical forest ecosystems with the aims of assessing the importance of plant litter in forest ecosystems for the biogeochemical cycle. Then, the major factors that affect the plant litter production and decomposition were identified, which could direct and contribute to future research. The small set of studies reviewed in this paper demonstrated the potential of plant litter to improve the biogeochemical cycle and nutrients in the forest ecosystems. However, further researches are needed particularly on the effect of species, forest structures, seasons, and climate factors on the plant litter production and decomposition in various types of forest ecosystems.

• 한국해양학회지:바다
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• 제27권1호
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• pp.1-16
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• 2022

질산염은 대한해협의 생태계 및 어업에 있어 중요한 영향을 준다. 관측을 기반으로 한 선행연구들은 해류가 질산염 수송에 중요한 영향을 줄 가능성을 제시하였다. 그러나 해류에 의한 질산염 수송과 생지화학적 요인에 의한 질산염 유출입의 정량적인 평가에 대한 연구는 없었다. 본 연구에서는 해류와 생지화학학적 요인에 대한 질산염 유출입의 계절 및 공간적인 변화를 2011년부터 2019년까지 물리-생지화학 결합 모델을 수행하여 살펴보았다. 모델 결과 분석을 통해 대한해협은 해류로 인해 질산염이 공급되며 공급된 질산염은 식물 플랑크톤의 섭식에 의해 소비됨을 알 수 있었다. 해류에 의한 질산염 수송량 중 제주도와 큐슈지역을 통과하는 해류에 의한 질산염 수송이 가장 컸으며 제주해협을 통과하는 해류에 의한 수송량은 이보다 1/3배 적었다 대한해협 서수도로 유출되는 질산염 수송량은 동수도로 유출되는 양보다 2배 더 많았다. 월 평균 질산염 순 유출입을 살펴보면 제주해협과 제주도와 큐슈를 통과하는 해류로 인해 공급된 질산염이 1월을 제외한 연중 대한해협에서 생지화학적 요인에 의해 순 유출되고 있었고, 이로 인해 대한해협을 통과하여 동해로 유입되는 질산염 수송량이 감소함을 알 수 있었다.

• Journal of the korean society of oceanography
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• 제39권2호
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• pp.136-147
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• 2004

Different model formulations in available models were compared with Microplankton-Detritus (MPB) model, and well documented FDM and ERSEM models were the candidate for these comparison. Different formulations in both candidate models were expressed in terms of MPD parameterization. Even though there are differences in the control of autotroph growth among models, it was found that some of the more important microplankton parameters expressed incomparable terms have broadly similar values in all the models. However, an important difference was proved to be the direct contribution of microheterotrophs to the Detritus compartment in FDM and ERSEM, whereas in MPD microplankton biomass passes to Detritus only by way of mesozooplankton grazing.

• 한국지구과학회지
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• 제40권4호
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• pp.392-405
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• 2019

Biogeochemical processes play an important role in ocean environments and can affect the entire Earth's climate system. Using an ocean-biogeochemistry model (NEMO-TOPAZ), we investigated the effects of changes in albedo and wind stress caused by phytoplankton in the equatorial Pacific. The simulated ocean temperature showed a slight decrease when the solar reflectance of the regions where phytoplankton were present increased. Phytoplankton also decreased the El $Ni{\tilde{n}}o$-Southern Oscillation (ENSO) amplitude by decreasing the influence of trade winds due to their biological enhancement of upper-ocean turbulent viscosity. Consequently, the cold sea surface temperature bias in the equatorial Pacific and overestimation of the ENSO amplitude were slightly reduced in our model simulations. Further sensitivity tests suggested the necessity of improving the phytoplankton-related equation and optimal coefficients. Our results highlight the effects of altered albedo and wind stress due to phytoplankton on the climate system.

• Ocean and Polar Research
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• 제44권1호
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• pp.83-97
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• 2022

The Amundsen Sea in West Antarctica is one of the most affected regions by climate change, but it is one of the least studied realms due to difficulties in access. Korea Polar Research Institute (KOPRI) launched a research project in the Amundsen Sea in 2010 using the icebreaker research vessel (IBRV) Araon and has been conducting various research initiatives. In this paper, previous researches derived from the Amundsen Sea Embayment by Korean researchers are introduced. Through previous studies, researchers have been able to interpret the environmental and biogeochemical changes according to the inflow Circumpolar Deep Water (CDW) and provide information for climate models. In particular, researches using radiocarbon isotopes (¹⁴C) were introduced to understand the physical and biogeochemical mechanisms of the carbon cycle in the Amundsen Sea. Opportunely, with the construction of a second icebreaker research vessel, the direction for systematic and long-term polar data acquisition can be presented.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2017년도 추계학술논문요약집
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• pp.149-150
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• 2017

• Ocean and Polar Research
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• 제30권3호
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• pp.325-334
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• 2008

A biogeochemical model was used to estimate air-sea $CO_2$ exchange over the East China Sea. Since fresh water discharge from the Changjiang River and relevant chemistry were not considered in the employed model, we were not able to produce accurate results around the Changjiang River mouth. This factor aside, the model showed that the East China Sea, away from the Changjiang River mouth, takes approximately $1.5{\sim}2\;mole\;m^{-2}yr^{-1}$ of $CO_2$ from the atmosphere. The model also showed that biological factors modify the air-sea $CO_2$ flux by only a few percent when we assumed that biological activity increased two-fold. Therefore, we can argue that the biological effect is not strong enough over this area within the framework of the current phosphate-based biological model. Compared to the preindustrial era, in 1995 the East China Sea absorbed $0.4{\sim}0.8\;mole\;m^{-2}yr^{-1}$ more $CO_2$. If warming of the sea surface is considered, in addition to the increase in atmospheric $CO_2$ concentration, by 2045 the East China Sea would absorb $0.2{\sim}0.4\;mole\;m^{-2}yr^{-1}$ less $CO_2$ compared to the non-warming case.

• 한국광물학회지
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• 제26권4호
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• pp.219-228
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• 2013

방사성 폐기물을 지하에 장기 보관하는 금속 용기에 관한 생지화학적 부식 특성을 알아보기 위해 주철과 구리로 된 금속재료를 환원조건 하에서 디설프리칸스 황산염환원미생물과 3개월간 반응시켰다. 금속재료의 화학적/광물학적 변화를 알아보기 위해 주기적으로 용존 금속이온들의 농도를 측정하였으며, 실험이 종료된 이후 금속 시편 및 표면 이차생성물들을 전자현미경을 이용하여 분석하였다. 디설프리칸스가 없는 조건에서는 금속재료의 부식이 매우 미약하였으나, 미생물이 있는 경우에는 부식이 상대적으로 컸다. 관찰된 생지화학적 부식 산물은 주로 맥키나와이트와 황화구리 같은 검은색의 금속황화물이었으며, 표면에서 쉽게 분리되거나 콜로이드화되어 부유하였다. 특히, 구리 시편의 경우 용액 상에 용존 철이 존재할 때 세균에 의한 구리 부식의 가속화가 관찰되었는데, 이는 구리 표면에 다른 종의 황화철이 성장하면서 구리 간의 결속력을 약화시켰기 때문인 것으로 보인다.